There is an ever increasing demand for easily processed thermoplastic resins which are thermally stable at higher and higher temperatures. Recent developments have produced many heavily aromatic compounds having the desired thermostability but lacking the desired processibility.
A key in developing a thermally stable and melt processible resin is maintaining adaquate flexibility along the polymer chain. The efforts which produced the subject invention were directed toward the general goal of synthesizing a polyimide precursor which would react with conventional diamine-terminated type compounds to form alkylene-linked polyimide resins. Therefore, it is an object of this invention to provide an alkylene-linked aromatic dixylyl compound which may be readily oxidized and dehydrated to form the corresponding dianhydride, which in turn will react with the aforementioned amine type compounds to form a thermally stable and yet easily processed polyimide resin.
It is a further object of this invention to provide a method of synthesizing an alkylene-linked dixylyl compound at relatively high yields by limiting the rates of the several competing reactions which may occur during the electrophilic substitution reaction.